A BIOS (Basic Input Output System, basic input output system) program is a set of programs permanently stored in the motherboard memory chip of a computer, and includes the most important basic input output programs, system setting information, power-on self test program, system boot program of the computer, and so on, and its main function is to provide the lowest-layer and most direct hardware setting and control for the computer.
POST (Power-On Self Test, power-on self test) is a function set by the BIOS program, and refers to a process of performing a self test for each hardware device in a system by running the BIOS program when a computer device is powered on and started, including the test for the CPU, memory, motherboard, storage device, floppy and hard disk subsystems, and so on; if the test result is normal, the operating system is booted, and if a hardware device is faulty, the operating system cannot be started. The power-on self test information refers to the test result in the POST process, including information such as hardware type and version, and according to the power-on self test information, the location of the fault may be determined.
To implement fault handling, the power-on self test information needs to be output to determine the location of the device fault according to the power-on self test information. The conventional method for outputting power-on self test information usually uses a motherboard diagnostic card to display all power-on self test information in the form of codes when the BIOS program performs a power-on self test.
In the actual work, first the motherboard diagnostic card is inserted into the PCI or SAI slot of the motherboard, and after the computer is powered on and started, the BIOS program performs a power-on self test operation to test the hardware devices one by one, and writes hardware codes to port 80 when performing a test operation, where the port 80 is an IO port with a fixed address for outputting BIOS running state information, and the hardware codes represent different power-on self test information. The motherboard diagnostic card reads the hardware codes written in the port 80, and displays the hardware codes through a nixie tube and LED display on the motherboard diagnostic card. If a test is successful, the BIOS program continues to write a next hardware code to the port 80 until the test is completed. If the test is not successful, it indicates that a hardware device is faulty. In this case, the BIOS program stops the test, and the codes currently displayed by the motherboard diagnostic card do not change, and the location of the fault is known according to the currently displayed codes.
As can be seen from the above process, the conventional method for outputting power-on self test information requires a motherboard diagnostic card to output power-on self test information, therefore, device resources are increased, and it is inconvenient to use the motherboard diagnostic card because the motherboard diagnostic card needs to be inserted into the motherboard and it is necessary to open the chassis where the motherboard is located, making the operation troublesome.